Method of intermittently casting variably colored thermoplastics



" 1941- 1.. H. MORIN ETAL 2,227,461

METHOD OF INTERMITTENTLY CASTING VARIABLY COLORED .IHERMOPLKSTICS Filed March 18, 192:7 smu -sham .1

II J'il Jan. 7, 1941. MQRIN ETAL 2,227,461

METHOD OF INTERHITTENTLY CASTING VARIABLY COLORED THERMOPLASTICS Filed March 18, 1957 2 Sheots.Sheet 2 I NVENTORS laws 1;. Mom/1v 04 V16 MAMA 5k) Patented Jan. 7, 1941 UNITED STATES PATENT OFFICE METHOD OF INTERMITTENTLY CASTING VARIABLY' COLORED THERMOPLASTICS Louis H. Morin and Davis Marinsky, Bronx, N. Y.,

assignors ,to Whitehall Patents Corporation, Bronx, N. Y., a. corporation of New York Application-March 18, 1937, Serial No. 131,608

8 Claims. '(01. 18-59) This invention relates to the molding or die casting of thermoplasties, such for example, in the casting of the links or scoops of separable fastener stringers; and the object of the invention is to provide a method which consists in intermittently and periodically casting upon a single workpiece or supporting member, such for example, as the tape or stringer of a separable fastener, a series of differently colored or contrastingly colored cellulose acetate elements in any desired grouping or arrangement to produce a predetermined design on the resulting article or a pair of articles coupled together; a further object being to provide a method of intermitl5 tently and periodically casting two or more different types and kinds of die casting materials which consists in providing independent units for the supply of the respective materials for delivering, heating and injecting the same into 90 a single mold or die by moving the respective units into position to register with the admission orifice or gate of the die; and with these and other objects in view, the invention consists in a method of casting thermoplastic materials 25 which is more fully hereinafter described and claimed. p

The invention is fully disclosed in the following specification, of which the accompanying drawings form a part, in which the separate parts oi our improvement are designated by suitable reference characters in each of the views, and in which:

Fig. 1 is a diagrammatic sectional view illustrating one use of our improved method.

35 Fig. 2 isa'diagrammatic sectional view subjstantially on the line 2--2 of Fig. 1.

Fig. 3 is a diagrammatic sectional view substantially on the line 3-3 of Fig. 2.

Fig. 4 is a view similar to Fig. 3 showing parts ina different position. c

Fig. 5 is a view similar to Fig. 1 showing only a part of the construction and with parts in a different position.

Fig. 6 is a detail view of two fastener stringers.

45 made according to our invention and shown in coupled relationship. i

Fig. 7 is a View similar to Fig. 6 showing the stringers coupled together in a different manner: and.

i Fig. 8 is a view similar to Fig. 6 and showing one of a number of other forms, of construction "which may be employed.

To illustrate one method of carrying the invention into effect, the accompanying drawings as diagrammatically illustrate methods of die casting the links or scoops of separable fasteners onto the mounting tapes or stringers employed. In. Figs. 6, 7 and 8 of the drawings, certain forms and arrangements of links are shown to produce so as to produce an effect similar to that shown in Fig. 7. Other staggered or irregular arrangements may be made of the two similar stringers by simply shifting one stringer longitudinally of the other, and this can be controlled in the manufacture of the stringer tapes.

In Fig. 8 of the drawings, one of the many other types and forms of stringer tapes is shown. I

In this construction, white and black links H, I la are alternately cast on the edge of the stringer tapes ID, llla to produce the result illustrated. In this connection, it will be understood that any desired form and arrangement or grouping of links of contrasting colors or other characteristics may be made, and an odd arrangement such as one white and two black or six white and four black, etc. can be provided. The various patterns or designs are controlled by the machine operation through suitable cams, jacquards or other means. While the invention herein described is shown as applicable to the manufacture of separable fastener stringers, this is only illustrative of one of many uses to which the invention may be applied. To give oneother specific example, it will be apparent that a plurality of die cast beads, knobsor other elements of difl'erent colors may be arranged longitudinally of a string or strand in forming what is known as pull chains. 40

In Fig. 1 of the drawings, we have diagrammatically illustrated a sectlon'through one unit of the mechanism for carrying the method into elfect and forming the links of a separable fastener stringer. In this figure, i2 represents a hopper casing having independent hopper compartments l3, lid with slides M, Ma movable across the discharge opening i5, 15a of said compartments. The slides have apertures i6, Ilia for measuring predetermined quantities of a suitable thermoplastic material l1, Ila fordelivery into independent cylinders l8, Ila of a cylinder block 19 as will be seen upon a consideration of Figs. 1 and 2 of the drawin s.

The casting or molding material 11, Ha may be in the form of particles, granular or powdered, of thermoplastic material, such for example as cellulose acetate. In some instances, and as seen in Fig. 1 of the drawings, an agitator 20 may be disposed in each hopper to stir thematerial I! to insure a feed thereof through the discharge opening I5. In some instances, a biscuit, capsule or the like of the required volume may be fed into and through the machine, either from a hopper or by removal from a rod in the manner taught in a companion application filed March 18, 1937, Serial No. 131,606.

Arranged below the casing I2 and in alinement with the apertures ll, Ila and in position to register with the apertures Il, Ila of the slides I4,

Ila are curved discharge or feed tubes 2I, 2Ia, the lower ends of which preferably extend toward each other to provide a closer arrangement of the cylinders Il, Ila and to dispose the lower ends of the tubes 2 I, 2 la above and in registering alinement with apertures 22, 22a in the block I9 and registering with the cylinders Il, Ila. The forward or discharge end of each cylinder is heated by an electric heating coil 23, only one of which is shown in Fig. 1 of the accompanying drawings. This coil is in circuit with a pyrometer 24' through wires 25. At 28 is shown suitable pyod means also in circuit with the pyrometer for registering temperature at the discharge end of the nozzle in order that the thermoplastic material may be heated to the desired degree to insure the formation of proper castings. At the rear portion of the block I8 is shown means 21 whereby water or another cooling agent may be passed through the block to cool the rear ends of the cylinders.

In each cylinder ll, Ila is arranged a piston or plunger 28, to the outer end of which is coupied the forked end 29 of the slides I, Ila. These pistons are operated by suitable means and at the proper time intervals in the cycle of operation for discharging or electing the material from the cylinders into the impression or mold cavity ll of the separate die parts ll, lIa. These pistons are actuated through resilient means to compensate for'varying conditions as later described.

Arranged on a bed plate or table 32 of the machine is a guide or slideway- 33 in which the lower flanged end Ila of the block is is slidably movable. The block Il has a iork-shaped extension 34 at one side carrying an anti-friction roller 35 which operates upon a cam 28 arranged on a shaft 31. Coupled with the otherside of the block I9 is a rod 38 which slides through a hearing 39. A spring 40 is arranged on the rod between the bearing 39 and the block is and serves to support the roller 35 in constant engagement with the surface of the cam ll.

The cam ll controls the shifting movement of the block I9 and the hopper casing 52 thereon as well as the other associated parts to bring the respective cylinders ll, Ila into registering alinement with the gate or admission opening ll on the parting line of the dies, or, in other words, in position to permit the ejection of the casting material .into the impression ll of the dies as well as to intermittently move the respective cylinders to one side of the aperture ll during each cycle of the machine or casting operation to prevent discharge of the material therefrom. A spring or springs 42 is employed to support the cylinders in firm engagement with the die parts spect to the dies to reduce frictional engagement, but not suiiicient to cause a leak or discharge 0 the heated casting material.

The cam ll is provided with one surface 43 maintaining the cylinder Ila in registering position with the die in making four successive iniections of the material Ila to form the four black links Ma. The bumps or raised cam surfaces 44 serve to move the cylinder Ila from the position shown in Fig. 3 to that shown in Fig. 4. At 45. we have shown the cam surface which supports the cylinder I8 in registering position with the die orifice 4|. This surface has spaced projections 48 which accomplish the same result described in connection with the cylinder Ila and shown in Figs. 3 and 4 of the drawings. The cam surface 45 will be such as to care for four discharges of the material to produce the four white cast links II as shown in Figs. 6 and 7 of the drawings. Suitable means will be provided to time the rotation of the cam ll or the shaft l'l thereof to provide eight distinct-charges or piston operations in each cycle or revolution of the cam ll. At this time, it will be apparent that when varied arrangements of castings are employed. diiierent types of cams, iacquards or other controlling means will be provided.

It is also within the scope of the present invention to provide two distinct sets of dies opening and closing "at the same time and being charged by two cylinders so as to form, for example, a black casting on one mounting member between one set of dies and a white casting on another mounting member between the other set of dies and the cylinders shifted to register with the opposed mounting members and dies to cast a series of the opposed colors on said diiferent mountin members.

It is understood at this time that it is within the spirit of the invention to provide rotary movement as well as sliding movement to the supply hoppers and the cylinders. While the invention as shown and described is illustrative of casting two different colors, a plurality of colors may be cast, in accordance with the fundamental and basic teachings of the inven tion which reside not in any particular mechanism employed but in a method of casting alternate and individual elements or groups of elements on a mounting member in diilerent colors or shades. It is also within the scope of this invention to not only cast solid colors in each link or element but to utilize the teachings of a companiomapplication in casting each link or element in two colors or shades in a definite relationship or in an irregular or mottled condition.

After making each casting, the link or element is stripped from a core pin 41 and the tape I0 is moved to bring the next section thereof in position between the dies to receive the next link to be cast. As the links and the tape are fed downwardly, the gate ll may be knocked or trimmed off from the end of the link by a suitable means ll. I

Considering Fig. 1 of the drawings, it will appear that the tape III may be treated with a suitable cement or solvent just prior to the application of the links thereon by passing the tape between a suction pipe or tube 50 and a feed tube 5|, both being in registering alinement so that a cement or solvent 52 in a suitable container 53 may be applied to the tape. In the feed of the casting material II, I'Ia, such for example, as cellulose acetate, in the respective The dies 3|, 3|a are cooled by the circulation I of water or another cooling agent throughfpas sages 54, 54a, arranged adjacent the impression,

or mold cavity 30 and having discharge tubes 55, tea as illustrated in Fig. 3c! the drawings.

While it has been stated throughthe specification that two differently colored thermoplastics may be used'in forming the successive series of die castings, it is within the scope of this invention to cast two different types of materialssuitable for die casting operations which would vary not only as to color but as to struc ture. For example, it is possible to make a com-1 hined plastic and metallic casting-Lit being un' derstood that separate heating units will be provided for the separatematerials in order to control the melting point or to bring the different materials to the desired temperature suitable for performing the casting operation. This combination would find its usefulness in mahing, for example, a pull chain onwhich would be arranged a combination of plastic and metallic beads or other members in spaced relation there on, the spacing being controlled by the means provided for moving the respective casting cylindex-s into registering position with the impression of the die. By cooling the inner ends of the cylinders l8, Ida, the pistons operating therein will be kept cool, thus preventing clogging or congestion oi the cylinders.

Instead of utilizing uniform colors in each of the hoppers as at H, Ila, each hopper may contain materials of variegated colors and a greater amount oi. one color to provide a base or ground color for the resulting castings to be formed. For example, if a white base color is desired, blue and red particles may also be included to produce on the resulting casting a white base or ground color with red and blue blotches appearing thereon, whereas the black base may include white, yellow, red or any other contrasting color. In using the muitiplecolors, it would also be desirable in some instances to use relatively large particles of the supplemental or mottling colors and finer particles of the ground color to produce a more definite contrast in the resulting casting. However, in some cases, there will be some blendingof the colors in the resulting casting. One set of castings arranged on a single mounting membermay be of solid unitary color and the other set of variegated colors.

Having fully described our invention, what we clagnii as new and desire to secure by Letters Paten s:

1. The herein described method of casting successive series of different colored thermoplastic members which consists in providing relatively movable die parts with a mold chamber between adjacent surfaces thereof, feeding one colored thermoplastic material into one cylinder and feeding another colored thermoplastic material into an independent cylinder, heating the materials at the discharge ends of the cylinders to plastic form, intermittently moving the respective cylinders separately into registering alinement with the mold chamber of the dies, pressure discharging the heated material from the the die parts, and controlling the movement of the cylinders into registering or casting positionwith respect to the dieparts to govern the number of successive castings produced by the material in one cylinder with respect to the castings produced by the material of the other cylinder.

2. The. herein described method offorming independent thermoplastic die castings, which consists in providing relatively movable die parts with an impression formed between adjacent surfaces thereof with an admission passage opening into the impression on the parting line of the die parts, feeding thermoplastic material into independent cylinders arranged in juxtaposition to each other, heating the material in said cylinders at thedischarge ends thereof, intermittently moving the respective cylinders into registering position with the admission passage to said impression, and selectively, discharging the material from said cylinders when the respective cylinders are in registering position with said admission passage to produce die castings intermittently formed from the materialsin the"respective cylinders.

3. The herein described method of forming independent thermoplastic die castings along a mounting member, which consists in providing relatively movable die parts with an impression formed between adjacent surfaces thereof with an admission passage opening into the impression on the parting line or the die parts, feeding thermoplastic material into independent cylinders arranged in juxtaposition to each other,

. heating the material in said cylinders at the discharge ends thereof, intermittently moving the respective cylinders into registering position with the admission passage to said impression, selectively discharging the material from said cylinders when the respective cylinders are in registering position with said admission passage to produce die castings intermittently formed from the materials in the respective cylinders, and controlling the movement of the respective cylinders into registering position with said admission passage to produce a predetermined series of successive castings from the respective materials employed.

i 4. The method of forming thermoplastic castlogs on a mounting member, which consists in intermittently moving relatively movable dies toward and from spaced sections or areas of the mounting member to register with the mold cavity of the dies, and intermittently pressure injecting diflerent colored thermoplastic materials from independent sources of supply into the mold cavity of the dies when intermittently engaging spaced sections of the mounting member to form differently colored castings on said spaced sections of a short length of said mounting member.

5. The method of forming thermoplastic castings on a mounting member, which consists in intermittently moving relatively movable dies toward and from spaced sections or areas of the mounting member to register with the mold cavity of the dies, intermittently pressure injecting different colored thermoplastic materials from independent sources of supply into the mold cavity oi the dies when intermittently engaging spaced sections of the mounting member to form differently colored castings on said spaced sections of a short length or said mounting member, and selectively controlling the injection of the different colored materials into the mold cavity to regulate the grouping and arrangement of cylinders when registering with the chamber of thermoplastic castings on the mounting member.

6. The herein described method of casting successive series of thermoplastic members, which comprises pressure injecting heated thermoplastic material, first from one source of supply to a mold cavity defining the member to be formed, then pressure injecting heated thermoplastic ma.- terial from another source of supply into the same mold cavity after removal of the cast member formed from the first source or supply, and controlling the succession of members cast from the respective supplies of heated thermoplastic material in the successive series of castings formed.

7. The herein described method 01 forming multi-colored die cast elements on a mounting member which comprises casting a variable and controlled number of elements on said member within dies surrounding said member from a source of supply of one color, then casting a variable and controlled number of elements on said member'within said dies from another source 01 supply of a difl'erent color and successively repeating the above mentioned steps in a continuous uninterrupted series of casting operations to provide predetermined groups of diil'erent colored elements in predetermined arrangement on said member.

8. The herein described method of casting suc-' cessive series of thermoplastic members, which comprises pressure injecting heated thermoplas tic material, first from one source of supply to a mold cavity defining the member to be formed, then pressure injecting heated thermoplastic material from another source of supply into the same mold cavity after removal 01 the cast member formed from the first source of supply, controlling the succession of members cast from the respective supplies of heated thermoplastic material in the successive series 01 castings iormed, sealing one source of supply against the discharge of material therefrom while the other source of supply is in injecting position, and sealing both 2 sources of supply intermediate successive series of castings.

LOUIS H. MORIN. DAVIS MARINSKY. 

